Field of the Invention
The present invention relates to an information display apparatus and an information display method.
Priority is claimed on Japanese Patent Application No. 2013-124832, filed Jun. 13, 2013, the content of which is incorporated herein by reference.
Description of Related Art
Recently, research and development of AR (Augmented Reality) augmenting real environment perceived by human being have been becoming popular. Typical examples of using AR technology may be mobile terminals such as smart phones superimposing, on the image of the real environment, additional information which depends on an image picked-up by an accessory camera, and displaying the superimposed image on a display apparatus. Capability for AR technology to add any types of information to the real environment will allow a wide variety of application of the AR technology to amusement such as games, guidance in museums or event sites, and medical support.
AR technology set forth above is classified into “Location-based AR” and “Vision-based AR”. “Location-based AR” is a technology presenting information by using location information obtained from GPS (Global Positioning System) or the like. “Vision-based AR” is a technology presenting information based on a result of recognizing an image picked-up by a camera. “Vision-based AR” is further classified into “Marker-based AR” presenting information by recognizing a predetermined graphic called “Marker” and “Marker-less AR” presenting information by recognizing a real object without using “Marker”.
Japanese Unexamined Patent Application Publication No. 2005-115500 discloses an example of an apparatus for presenting information by “Marker-based AR”. Specifically, Japanese Unexamined Patent Application Publication No. 2005-115500 discloses an apparatus recognizing a camera position (a distance between the marker and the camera) and an angle (an angle of the camera to the marker), obtaining information related to a position of the marker by reading a description of the marker, superimposing the obtained information on the image picked-up by the camera. Also, the patent reference discloses the apparatus matching the obtained information to the camera position and the angle, and displaying the superimposed image.
Japanese Unexamined Patent Application Publication No. 11-234651 unrelated to AR technology discloses a monitoring camera apparatus for obtaining a high visibility monitoring image on which a television signal and an image sensing signal for high speed image processing are superimposed. The monitoring camera apparatus disclosed in Japanese Unexamined Patent Application Publication No. 11-234651 includes a monitoring camera unit configured to obtain the television signal for image monitoring, an image sensing unit configured to obtain the image sensing signal for the high speed image processing, and a signal adding device configured to superimpose the television signal on the image sensing signal.
As described above, AR technology is a technology basically presenting (displaying) the augmented real environment to a user. The apparatuses disclosed in the patent references have a function of automatically adjusting white balance and exposure according to photographic environments such as brightness of a photographic object, existence or non-existence of a shadow, or the like. The apparatus adjusts the image to be easily viewable to a user, and displays the adjusted image.
Adjusting the camera-picked-up image to be easily viewable to a user can improve the visibility to the user regardless of the photographic environments. But the image adjusted to be easily viewable to a user is not always suitable for the image recognition. For this reason, for example, “Vision-based AR” described above is unable to recognize the image picked up by the camera and unable to provide the additional information.
In these situations, if the user continues photographing the photographic object while shifting the position of the mobile terminal device and turning the mobile terminal device, there will be a non-zero possibility that the additional information may be displayed. However, in a case where AR technology described above is used to support maintenance of field devices in a plant or a factory, no provision of the additional information will cause decrease in working efficiency and mistakes.
On the other hand, adjusting the camera-picked-up image to be suitable for the image recognition will reduce a risk that the additional information is not provided. However, it remains possible that the image adjusted to be suitable for the image recognition is not easily recognizable by the user. The above-described method of displaying superimposed image can cause a poor visibility to raise a risk that the image and the additional information are not easily recognizable by a user, resulting in possible decrease in working efficiency and some mistakes.